Automatic plug extraction device for ceramic molds



NOV. 17, 1970 GRAM ETAL AUTOMATIC PLUG EXTRACTION DEVICE FOR CERAMIC MOLDS Filed April 30, 1968 2 Sheets-Sheet 1 INVENTORS [en/w 6mm c/OHAAW Was; T 3 Jase JCHPEf'ZMA/f Nov. 17, 1970 E. GRAM ETAL 3,540,095

AUTOMATIC PLUG EXTRACTION DEVICE FOR CERAMIC MOLDS Filed April 30. 1968 2 Sheets-Sheet 2 INVENTORS Sen/w 04M Jami/w ass Y L/Uff/ZYC/gWE/Z/W/ikf? United States Patent 3,540,095 AUTOMATIC PLUG EXTRACTION DEVICE FOR CERAMIC MOLDS Erwin Gram, Johann Weiss, and Josef Schretzmayer,

Wilhelmsburg, Austria, assignors to Ospag Osterreichische Sanitar-Keramikund Porzellan-Industrie Aktiengesellschaft, Vienna, Austria Filed Apr. 30, 1968, Ser. No. 725,437 Claims priority, application Austria, July 7, 1967, A 6,367/ 67 Int. Cl. B28b 5/02 US. Cl. 25-29 3 Claims ABSTRACT OF THE DISCLOSURE Automatic plug extraction device for removal of slip from ceramic molds in the automatic manufacture of ceramic articles, such as toilet bowls and the like.

This invention relates to the manufacture of ceramic articles including toilet bowls, water closets, and the like, utilizing automatic procedures, and, more specifically, concerns novel and improved apparatus for the automatic extraction of plugs extending from the bottom of molds carried by suitable conveyers, such as track guided carriages. Known apparatus for the removal of plugs from molds on casting conveyers in the manufacture of toilet bowls and other molded articles after the desired ceramic wall thickness has been obtained involves tilting of the carriage relative to a fixed extractor in order to remove the plug. With these structures, the plug cannot be inserted deeply into the bore or opening in the bottom of the mold as the bore in the base plate of the mold which is usually made of gypsum will be seriously damaged. This occurs notwithstanding the fact that the opening or siphon in the base plate may have its edges slightly rounded with the result that the mold base plate becomes unserviceable even after relatively short use. Moreover, plugs which are inserted a short distance into the mold bore are often easily dislodged by the pressure of the infiowing slip which obviously interrupts continuous production of the articles. In the case of toilet bowls which are relatively large and contain a rather substantial quantity of slip, premature dislodging of the plugs has presented a serious problem.

This invention overcomes the difficulties heretofore encountered with prior apparatus and provides a novel and improved arrangement and organization of elements which enables the utilization of a relatively long plug firmly seated in the bottom of the mold, which plug is extracted in a direction substantially axially thereof during movement of the carriage in the course of production. Dislodgement of the plug in this manner avoids damage to the base of the mold, and, at the same time, enables the use of a plug of suflicient length which will prevent accidental dislodgement.

Another object of the invention resides in the provision of novel and improved automatic plug removing apparatus for the dislodgement of plugs utilized in the bases of molds, such as toilet bowl molds and the like, that affords positive extraction without damaging the mold base.

Still another object of the invention resides in the provision of novel and improved automatic extraction means for plugs utilized in the formation of ceramic articles.

The above and other objects and advantages of the invention will become more apparent from the following description and accompanying drawings forming part of this application.

"ice

In the drawings:

FIG. 1 is a fragmentary plan view of a carriage supporting track illustrating means in accordance with the invention for extracting plugs from molds supported by carriages;

FIG. 2 is a side elevational view in partial section of the structure shown in FIG. 1 and with a mold supporting carriage in position for extraction of the plug, the sectioned portions being taken along the line 11-11 of FIG. 3; and

FIG. 3 is a cross-sectional view of FIG. 2 taken along the line IIIIII thereof.

The apparatus now to be described is specifically intended for utilization in the automatic manufacture of toilet bowls with the molds being carried by carriages 2 movable over a pair of tracks 1 which guide the carriages through the successive operations in the formation of the completed bowl. The mold for the bowl is formed in a plurality of independent sections and for the purposes of this description, only the bottom portion 3 of the mold is illustrated on the carriage 2. The mold base 3 includes a bore 4 in which a plug 5 is firmly inserted. The plug 5 extends downwardly a distance below the carriage 2 and carries a flanged end portion 15 as will be observed more clearly in FIG. 3. The carriage 2 further includes a downwardly extending brace 12 having a bolt 13 extending transversely thereof and fixed securely to the brace.

As will be observed as the description proceeds, the bolt 13 actuates the extracting mechanism to engage the lower end of the plug 5 and exert vertical motion to the plug to extract it from the bore 4.

The plug extracting mechanism in the illustrated embodiment of the invention includes a movable track section 6 hinged to the basic track section 1 by a pin 7. The track section 6 is movable upwardly about the pivot 7 but is limited in its downward motion by a stop 16 formed of rubber or other suitable material which maintains it normally coplanar with the adjoining portions of the track 1. The upper or inner edge of the track section 6 as viewed in FIG. 1 carries an essentially tubular element 9 which, in the instant embodiment of the invention, is inclined downwardly in the direction of movement of the carriage 2 as illustrated by the arrow 8. While the tubular member 9 is of arcuate configuration, it may, of course, be linear. The upper surface of the tubular member 9 has a longitudinal slot 11 so that as the carriage 2 approaches the element 9 the bolt 13 carried by the bracket 12 will engage the edges of the slot 11 While the bracket 12 will move through the slot 11.

The upper edge of the tubular member 9, as shown in FIG. 1, further includes a fork or U-shaped element 10 with the legs of the fork 10 being spaced a distance slightly greater than the shaft of the plug 5 so that the fork will engage the flanged portion 15 on the bottom of the plug. A spring 14 is disposed between the trailing end of the track section 6 and a portion of the fixed frame of the apparatus to hold the track section 6 in the horizontal position, as illustrated in FIGS. 1 and 2.

With the arrangement as described above, as the carriage is moved over the track section 6, the bolt 13 carried by the bracket 12 engages the tubular member 11 and by reason of the angular disposition of this member, the bolt 13 will lift the member 11 together with the track section 6 against the action of the spring 14. This action raises the fork 10 to a level sufficient to permit the fork to engage the flanged portion 15 of the plug 5 as illustrated in FIG. 3. Continued motion of the carriage 2 will move the pin 13 out of engagement with the tubular member 9 whereupon the spring 14 will forcibly pull the fork 10 downwardly and in so doing it will extract the plug 5 from the mold 3 and will not tilt the plug during the course of extraction. Since the track section 6 is pivoted at a substantial distance in advance of the fork 10, the downward motion of the fork will be substantially linear.

While the fork may befabricated in any desired manner, in the illustrated embodiment of the invention it is formed of nagle iron bent in the form of a U.

While in most cases the fork 10 is preferably disposed between the tracks 1 which support the carriage 2, there are certain instances wherein so-called external plugs are employed, namely plugs which extend downwardly from the carriage at a point adjoining the outside of one of the tracks 1. In such cases, a fork 17 which is substantially identical to the fork 10 is secured to the outer or bottom surface of the track section 6 as viewed in FIG. 1.

While the invention described above is particularly useful in connection with the fabrication of toilet bowls which require relatively large molds, it is, of course, evident that it may be utilized in connection with the manufacture of other types of ceramic articles.

While only certain embodiments of the invention have been illustrated and described, it is apparent that modifications, alterations and changes may be made without departing from the true scope and spirit thereof, as defined by the appended claims.

What is claimed is:

1. Apparatus for extraction of a plug which closes an opening in the bottom of a mold in the manufacture of a ceramic article comprising a carriage supporting said mold, tracks supporting and guiding said carriage, spring loaded plug extracting means beneath said carriage, means raising said extracting means as said plug approaches said extracting means, said plug having a depending portion engaging said extracting means as the carriage is advanced and means responsive to continued advancement of said carriage displacing said extracting means downwardly in a substantially vertical direction to extract said plug from said mold.

2. Apparatus for extraction of a plug which closes an opening in the bottom of a moisture absorbent mold in the fabrication of ceramic articles including toilet bowls to remove excess ceramic slip comprising a carriage carrying said mold, tracks supporting and guiding the movement of said carraige, said mold having an opening on the underside thereof, a plug closing said opening and having an enlarged lower end portion, a depending member fixed to said carriage, a spring loaded tubular mem ber having a slot in the upper surface thereof extending substantially parallel to said tracks, said tubular member fixedly pivoted relative to said tracks at a point in advance of the leading end, said leading end of said tubular member slidably engaging said fixed depending member upon movement of said carriage and displacing the tubular member upwardly against the action of said spring, a U-shaped extractor carried by said tubular member and movable therewith, said extractor being aligned with and engaging the lower end of said plug when said tubular member is in the raised position whereby disengagement of said tubular member by said depending member substantially linear downward movement of said tubular member and extractor thereby removing said plug and discharging excess slip from said mold.

3. Apparatus according to claim 2 wherein tubular member is curved and inclined downwardly in the direction of motion of said carriage and said extractor is carried by said tubular member at a point adjoining the trailing edge thereof.

References Cited UNITED STATES PATENTS 2,494,212 1/1950 Spriggs 2565 2,583,842 1/1952 Hendrickson 2529 X 3,448,497 6/1969 Arnold 2529 I SPENCER OVERHOLSER, Primary Examiner B. D. TOBOR, Assistant Examiner US. Cl. X.R. 266-42 

